function loadImg(src) {
    return new Promise((res, rej) => {
        const img = document.createElement('img');
        img.src = src;
        img.onload = () => {
            res(img)
        };
        img.onerror = () => {
            const err = new Error(`图片加载失败 ${src}`);
            rej(err);
        };
    })
}

// const url = 'https://img.mukewan.com/5a9fc8070001a82402060220-140-140.jpg';
// loadImg(url).then((img) => {
//     console.log(img.width);
//     return img
// }).then((img) => {
//     console.log(img.height);
// }).catch((ex) => {
//     console.error(ex);
// })

const url1 = 'https://img.mukewang.com/5a9fc8070001a82402060220-140-140.jpg'
const url2 = 'https://img3.mukewng.com/5a9fc8070001a82402060220-100-100.jpg'

loadImg(url1).then((img1) => {
    console.log(img1.width);
    return img1;
}).then((img1) => {
    console.log(img1.height);
    return loadImg(url2);
}).then((img2) => {
    console.log(img2.width);
    return img2;
}).then((img2) => {
    console.log(img2.height);
}).catch((ex) => {
    console.error(ex);
})